CX-020176: Southern Sector Humate Injection Pilot Test

Pursuant to encouraging results from the 2013/2015 Aerobic Bio-stimulation bench scale study using humate to treat Southern Sector groundwater contaminated with the solvents trichloroethylene (TCE) and tetrachloroethylene (PCE), Environmental Compliance & Area Completion Project (EC&ACP) and Savannah River National Laboratory (SRNL) initially obtained a Temporary Authorization (TA) from the South Carolina Department of Health and Environmental Control (SCDHEC) to pursue a field pilot at the M-Area Southern Sector recovery well SSR001 area.  However, the injection capacity of the upper screen of SSR001 diminished over time.  Savannah River Site (SRS) ceased the injection activities and with SCDHEC approval, removed the bulk of the humate solution from the tanks.  To determine if the humate amendment might be a viable option as a recommended corrective action, SRS proposed and SCDHEC approved a revised strategy of extracting groundwater from the lower portion of the Lost Lake Aquifer Zone (LLAZ) using screen zone SSR001B of recirculation well SSR001.  At the surface, the groundwater will be amended with dissolved humate, a macronutrient fertilizer, and an anti-foam agent, and injected into upgradient wells SSM001B, SSM037B, and SSM040CC to distribute these amendments in the LLAZ.  SCDHEC has approved this revised strategy.  The goal is to establish an enhanced attenuation zone with humate concentration in the aquifer at a level of 100 mg/L (500 mg/kg sorbed in the soil).  This will be followed by monitoring and periodic reporting, culminating with a final performance effectiveness status report in 2022.